1. Field of the Invention
The present invention relates to a biological tissue treating device, in which the treatment of the biological tissue, such as dissipation due to vaporization, incision, excision, coagulation and arresting of bleeding, is carried out in an electromagnetic field proximate to the tissue in the action of an electromagnetic energy of the electromagnetic field emanating from the tip of an electrode for irradiating an electromagnetic field, and more specifically to an electrode rod for treating a biological tissue, which rod is equipped with such an electrode for irradiating an electromagnetic wave.
2. Description of the Related Art
Generally, as shown in FIG. 8, a biological tissue treating device equipped with an electromagnetic electrode includes a high frequency power supply 1 for generating a high frequency current having a radio frequency of, for example, 8 MHz–60 MHz in a wide band, and the high frequency current generated by the high frequency power supply 1 is supplied to an electromagnetic wave irradiating electrode 5 via an impedance matching unit 3 and a high frequency current cable 11.
The high frequency current cable 11 comprises a core wire 2 and a shield tube 6, which coaxially surrounds the core wire 2 via an insulating material. The proximal end of the core wire 2 is connected to terminal 7a for one electrode of the high frequency power supply 1 via the matching unit 3, and the proximal end of the shield tube 6 is connected to terminal 7b for the other electrode of the HF power supply 1 via both the matching unit 3 and a lead wire 7. The electromagnetic wave irradiating electrode 5 can be mounted at one end of a removable core wire 2a connected to the distal end of the core wire 2 via a socket 11a. 
In FIG. 8, moreover, reference numerals 8, 9 and 10 mean a biological tissue, a local area thereof and a portion to be irradiated by the electromagnetic wave, respectively.
As shown in FIGS. 9 and 10, the conventional electrode rod for treating a biological tissue, which electrode rode includes an electromagnetic wave irradiating electrode 5 and a core wire 2a, is connected to a stainless steel electrode 5, and a heat resisting coating layer 12 is applied onto an conductor area extending from a flexible metal core wire 2a having a relatively small diameter to a rigid metal rod core wire 2b having a relatively large diameter. Since the electrode 5 is normally operated at an extremely high temperature (about 200° C.), the tip 12a of the insulation layer 12 is disposed away from the electrode 5 by a distance of several millimeters in order to avoid the burning up. Accordingly, such an exposed core wire 2a resides in the vicinity of the electrode 5 in the conventional electrode rod, and therefore the surface of such an exposed section becomes to be at a high temperature in the operation state. In this case, there is a possibility that a local portion other than that not to be treated in the biological tissue becomes into contact with the exposed section of the core wire, and then burns out, thus causing a disadvantage to be provided, since great skill is required in the operation of the electrode rod.